1. Field of the Invention
This invention relates to repair of pipes in which a segment requiring repair must be isolated from the remainder of the pipe.
2. Description of the Prior Art
Shutting off pipes to facilitate repair thereof is known; typical is the method and apparatus disclosed in U.S. Pat. No. 3,040,779. Also known are stoppers for closing off pipe sections, as disclosed in U.S. Pat. Nos. 1,946,138; 3,710,812 and 3,908,682. Pipe repair plugs and valves for tapping pipes are also known; see U.S. Pat. Nos. 2,399,544 and 3,973,584.
Of interest are U.S. Pat. Nos. 4,127,141 and 4,155,373. The '141 patent discloses a method and apparatus for sealing the opening in the side wall of a fluid carrying pipe during replacement of a service "T" associated with the pipe. Apparatus disclosed in the '373 patent facilitates closure of a pipe section.
While the apparatus disclosed in the prior art presumably functions successfully for its intended use, there is need for highly portable apparatus which can be easily transported to where a pipe has failed, attached to the pipe with minimal tools and used to shut-off the pipe segment requiring repair. Furthermore, there is need for lightweight portable apparatus which facilitates shut-off of a pipe segment without release of fluid within the pipe to the atmosphere. This is highly desirable especially when repairing pipes through which combustible gas flows.